Japan's approach to addressing climate change involves the use of a synergistic effect generated by the efforts of multiple concerned parties to achieve greater reductions in carbon dioxide (CO₂) emissions.

A data center refers to either a dedicated space or building that houses anywhere from a few hundred to several tens of thousands of computers. Recently, we have been facing the problem of rapidly increasing electricity consumption by data centers, which is attributable to growing information processing volume caused by the increased use of the Internet and computers for everything from information processing for business applications to the viewing of videos by individuals. Nevertheless, the increase in the absolute volume of information processing means that data centers are contributing to greater efficiency in social activities. Accordingly, while accepting this increase, we must strive to improve energy efficiency.

In the U.S., power usage effectiveness (PUE) has been adopted as an energy efficiency metric for data centers. While this metric reflects the energy-saving performance of support facilities in a data center such as air conditioning and power supply equipment, it does not measure that of the information technology (IT) equipment.

In Japan, a new metric known as a Data Center Performance Per Energy (DPPE) and four sub metrics constituting DPPE have been developed; this metric is being promoted internationally. The DPPE metric takes into account the energy efficiency of both the IT equipment and support infrastructure of a data center.

Japan's thinking behind DPPE is that if all the parties involved with a data center, including computer users, IT equipment suppliers and data center builders, strive to improve each sub-metric for which they are responsible, the overall synergistic effect will lead to major reductions in Greenhouse Gas emissions.